NEW YORK—Second-graders who can’t tie shoes or zip jackets. Four-year-olds in Pull-Ups diapers. Five-year-olds in strollers. Teens and preteens befuddled by can openers and ice-cube trays. College kids who’ve never done laundry, taken a bus alone or addressed an envelope.

Are we raising a generation of nincompoops? And do we have only ourselves to blame? Or are some of these things simply the result of kids growing up with push-button technology in an era when mechanical devices are gradually being replaced by electronics?